Lets look at this another way...

Rating: 1/10 (18 March 2006)

OK its England and everybody (almost) is dead or infected. Very scary too. The two main survivor characters are Selena (a black girl) and Jim (an Irish bloke), well thats very English. OK thats plausible but just why those group representatives exactly? (This is not to belittle the actors playing of their roles)
Not to worry though along come the British army, most of them are English, including their leader Christopher Ecclestone. IMDb tells us that:
"Christopher Ecclestone and the other soldiers in the film had a three-day training programme with real soldiers to help them learn how to carry themselves believably."
Believably?! Really? Or did they (Boyle, whoever etc) instead just have Ecclestone play the part of a crazed fascist and the squaddies act like a rabble of football hooligans in uniform. Hey, you really confounded our expectations there.
There is a more sympathetic soldier character but, just so we get the message, he is Scottish not English.